Retractable needle assembly and syringe utilizing the same

ABSTRACT

An injection device including a barrel, a hollow plunger having a portion structured and arranged to move within the barrel, a needle unit, and a safety system that one of automatically causes the needle unit to retract into the plunger when the plunger reaches a substantially fully depressed position and utilizes a frangible or breakable seal arranged within the plunger. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

CROSS-REFERENCE TO RELATED APPLICATIONS

The instant application is a US non-provisional application based onU.S. provisional application No. 61/167,741, filed Apr. 8, 2009, thedisclosure of which is hereby expressly incorporated by reference heretoin its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to syringes, e.g., hypodermic syringes,such are utilized for injection of medicament into the body tissues ofhuman and animal patients. More specifically, this invention relates toa hypodermic syringe having a plunger, piston and needle supportstructure or needle unit that permits retraction of the needle supportand its needle into the plunger of the syringe to prevent thepossibility of inadvertent needle pricks and which incorporates afrangible plunger seal that may be broken away to prevent subsequent useor re-use of the syringe.

This invention also relates to single-use syringes which automaticallyretracts the needle into the syringe when the plunger is substantiallyfully depressed which is more easily and/or less costly to produce.

This invention also relates to syringes which can be used only once,i.e., single-use syringes, and/or to syringes which utilize a built-insafety system which cannot be easily overridden by a user thereof.

2. Discussion of Background Information

In hospitals, nursing home facilities and the like, injection ofmedicament into the body tissues of patients is done on a daily basis.Typical hypodermic syringes are provided with a barrel having a needlethat is fixed or removably attached at one end thereof. A plungertypically having an elastomeric piston is movable within the barrel toload the barrel with liquid medicament by suction as the plunger andpiston are moved within the barrel in a direction away from the needle.After the needle has penetrated the body tissues of the patient, as thedirection of movement of the plunger and piston are reversed and thepiston is forced toward the needle, medicament contained within thebarrel will be injected through the needle into the body tissues.

After hypodermic syringes have been used in this manner, those syringesthat are disposable present a significant problem to users, e.g.,hospital or nursing home staff, because the possibility of inadvertentneedle pricks subject personnel to the possibility ofcross-contamination by, among other things, virile or bacterialcontaminants that might be present on the needle after its use. In aneffort to avoid the possibility of inadvertent needle pricks specialwaste containers are often provided at hospital facilities into whichthe used disposable hypodermic syringes are placed. These containers andthe syringes contained therein are then disposed of in a specificallyorganized manner to insure against the possibility of inadvertentinfectious contamination of nursing personnel. Further, refuse handlersand other persons who might inadvertently come into contact with theused hypodermic syringes are also subject to the same hazards. Oftentimes the needles themselves are bent over so as to minimize thepossibility of inadvertent needle pricks and to preclude the possibilityof subsequent use of disposable hypodermic syringes.

In certain situations, medicaments are injected into patients and notquickly thereafter discarded properly. Instead, the used syringe isplaced in a temporary position. After the procedure has ended, thesyringe can be manually recovered for disposal. However, between thetime of use and the time of disposal, there is the possibility thatinadvertent needle pricks will occur. Accordingly, it is desirable toprovide a suitable way protecting personnel, e.g., nursing personnel,paramedics and other persons, from the hazards of inadvertent needlepricks as they go about their daily tasks.

It is therefore desirable to provide a syringe that includes a systemfor rendering the needle thereof to a protected, completely encapsulatedcondition such that it is less likely to cause, after use, aninadvertent needle prick during its handling or during its disposal. Itis also desirable to provide a syringe having the capability of causingthe automatic retraction of the needle to a position inside the plungerof the syringe and maintaining the needle in its retracted position sothat the needle of the syringe is always enclosed after its use, thusprecluding the possibility that the needle might cause an accidentalneedle prick as the syringe is subsequently handled. It is alsodesirable to provide a syringe of the disposable type that is providedwith facility for rendering it completely inoperative such that it cannot be subsequently used. Additionally, it is desirable to provide for asyringe which also has minimal dead-space so that it can be ideally usedfor injecting very expensive medicaments with minimal waste. Finally, itis desirable to provide for a syringe which also has a system forselectively locking the plunger in a substantially fully depressedposition so that the syringe can have dual, multiple, and/or parallelsafety systems, i.e., one system can include causing the needle unit toretract into the plunger and another system can include locking theplunger in a substantially fully depressed position.

SUMMARY OF THE INVENTION

According to one non-limiting aspect of the invention there is providedan injection device comprising a barrel, a hollow plunger having aportion structured and arranged to move within the barrel, a needleunit, and a safety system that one of automatically causes the needleunit to retract into the plunger when the plunger reaches asubstantially fully depressed position and utilizes a frangible orbreakable seal arranged within the plunger.

The injection device may be a single-use syringe. The barrel maycomprise a cylindrically shaped internal space structured and arrangedto receive therein a medicine. The barrel may further comprise aproximal opening within which the needle unit is at least one of pressfit and in sealing engagement therewith. The plunger may comprise apiston arranged at a proximal area of the plunger and an actuating endarranged in front of the piston. The plunger may further comprise atleast one of the piston being an elastomer or rubber piston, a hollowspace sized and configured to receive therein the needle unit in itsentirety, and a locking member adapted to lock with a locking memberarranged on the barrel. The barrel, the plunger, and a hub portion ofthe needle unit may each comprise a synthetic resin material. The needleunit may comprise a generally cylindrical hub and a hollow needleprojecting from the hub. The needle may comprise at least one of metaland stainless steel. The barrel may comprise at least one releasableretaining member which releasably retains the needle unit in an initialposition. The barrel may comprise plural releasable retaining memberswhich each releasably retain the needle unit in an initial position. Thebarrel may comprise at least one deflectable retaining member whichreleasably retains the needle unit in an initial position. The barrelmay comprise plural deflectable retaining members which each releasablyretain the needle unit in an initial position.

The device may further comprise a locking arrangement that is structuredand arranged to lock a distal end portion of the plunger to the barrel.The device may further comprise a locking arrangement selectivelylocking a portion of the plunger to the barrel upon the plunger reachinga substantially fully depressed position. The device may furthercomprise a biasing member, wherein, when the plunger is moved to a fullinjection position, the needle unit is automatically caused to retractinto the plunger via the spring. The device may further comprise aspring arranged within the barrel, wherein, when the plunger is moved toa full injection position, the needle unit is automatically caused toretract into the plunger via the spring. The device may further comprisea system providing an indication to the user that further forwardmovement of the plunger will cause the needle unit to automaticallyretract into the plunger. The device may further comprise a systemproviding an indication to the user that at least one of the plunger hasreached a full injection position and the further forward movement ofthe plunger will cause the needle unit to automatically retract into theplunger.

According to one non-limiting aspect of the invention there is provideda syringe comprising a barrel, a plunger having a portion structured andarranged to move within the barrel, a needle unit, and a safety systemthat one of automatically causes the needle unit to retract into theplunger when the plunger reaches a substantially fully depressedposition and utilizes a frangible or breakable seal arranged within theplunger.

The syringe may further comprise a system providing an indication to theuser that the plunger has reached a full injection position and thefurther forward movement of the plunger will cause the needle unit toautomatically retract into the plunger.

According to one non-limiting aspect of the invention there is provideda single-use syringe comprising a barrel, a hollow plunger having aportion structured and arranged to move within the barrel, a needleunit, and a safety system that one of automatically causes the needleunit to retract into the plunger when the plunger reaches asubstantially fully depressed position and utilizes a frangible orbreakable seal arranged within the plunger.

The syringe may further comprise a system providing an indication to theuser that the plunger has reached a full injection position and thefurther forward movement of the plunger will cause the needle unit toautomatically retract into the plunger.

According to one non-limiting aspect of the invention there is provideda method of using the injection device described above, wherein themethod comprises moving the plunger away from the needle unit so as tocause a desired amount of medicine to enter into the barrel and movingthe plunger towards the needle unit so as to cause medicine to exit thebarrel through the needle. The method may further comprise locking theplunger to the barrel to prevent re-use of the syringe.

Other exemplary embodiments and advantages of the present invention maybe ascertained by reviewing the present disclosure and the accompanyingdrawing.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described in the detailed descriptionwhich follows, in reference to the noted plurality of drawings by way ofnon-limiting examples of exemplary embodiments of the present invention,in which like reference numerals represent similar parts throughout theseveral views of the drawings, and wherein:

FIG. 1 shows a side cross-section view of a first non-limitingembodiment of the device according to the invention. The needle is notshown in cross-section. FIG. 1 shows the device with a safety capinstalled thereon. The device is in an initial prior-use and/or packagedconfiguration;

FIG. 2 shows the device of FIG. 1 after the safety cap is removed and ina ready-to-use position;

FIG. 3 shows the device of FIG. 2 with the plunger retracted as wouldoccur when medicine is caused to be suctioned into the syringe via theneedle;

FIG. 4 shows the device with the plunger fully depressed as would occurduring injection. In this position, the leading end of the plunger hasmoved deflectable retaining members out of locking engagement with theneedle hub. Moreover, a rear end of the needle hub has caused an innerseal, i.e., a frangible plunger seal, to come out of sealing engagementwith the needle hub;

FIG. 5 shows the device after the needle unit is caused to automaticallyretract into the plunger under the biasing force of a spring. Theconfiguration shown in FIG. 5 occurs automatically when the plungerreaches the position shown in FIG. 4;

FIG. 5 a shows a rear end view of the device of FIG. 5;

FIG. 6 shows an enlarged partial view of the device of FIG. 4 justbefore the plunger reaches the fully depressed position;

FIG. 7 shows an enlarged partial view of the device of FIG. 4 just asthe plunger reaches the fully depressed position thereby causingdeflection of the retaining members and breaking of the frangibleplunger seal caused by movement of the plunger against a rear end of theneedle hub;

FIG. 8 shows a side cross-section view of the plunger used on the firstnon-limiting embodiment shown in FIG. 1 and with the plunger piston andinner seal removed;

FIG. 9 shows a side view of the plunger of FIG. 8 with the plungerpiston installed thereon;

FIG. 10 shows a side cross-section view of the plunger piston used onthe plunger shown in FIG. 9;

FIG. 11 shows a side view of the plunger piston shown in FIG. 10;

FIG. 12 shows a side view of the inner seal used on the plunger shown inFIG. 1;

FIG. 13 shows a front end view of the inner seal shown in FIG. 12;

FIG. 14 shows a side cross-section view of the inner seal shown in FIG.12;

FIG. 15 shows a side cross-section view of the device shown in FIG. 1with the plunger removed;

FIG. 16 shows a side cross-section view of the syringe body used in thedevice shown in FIG. 1;

FIG. 17 shows a rear end view of the syringe body shown in FIG. 16;

FIG. 18 shows a rear end view of another embodiment of the syringe body;

FIG. 19 shows a rear end view of still another embodiment of the syringebody;

FIG. 20 shows a side view of the needle unit used in the device shown inFIG. 1;

FIG. 21 shows a side cross-section view of the needle unit shown in FIG.20;

FIG. 22 shows a rear end view of the needle unit shown in FIG. 20;

FIG. 23 shows a side cross-section view of the spring used in the deviceshown in FIG. 1;

FIG. 24 shows a rear end view of the spring shown in FIG. 23;

FIG. 25 shows a side cross-section view of the needle sealing guidemember used in the device shown in FIG. 1;

FIG. 26 shows a side view of the needle sealing guide member shown inFIG. 25;

FIG. 27 shows an enlarged partial view of another embodiment of aplunger which can be used on a device of the type shown in FIG. 1. Theplunger is similar to that used in FIG. 1 except that the inner seal isaxially retained within the plunger via a separately formed ring;

FIG. 28 shows an enlarged partial view of a modified version of thedevice of FIGS. 1 and 6. In this embodiment, the device of FIGS. 1 and 6is modified to include a puncturable sealing washer to provided sealingbetween the needle and the syringe body;

FIG. 29 shows an enlarged partial view of another modified version ofthe device of FIGS. 1 and 6. In this embodiment, the device of FIGS. 1and 6 is modified to eliminate the needle sealing guide and to insteadinclude a puncturable sealing washer to provided sealing between theneedle and the syringe body;

FIG. 30 shows a side cross-section view of the device shown in FIG. 29with the needle unit and spring removed;

FIG. 31 shows a cross-section view through the section (indicated byarrows) shown in FIG. 30;

FIG. 32 shows an enlarged partial view of another modified version ofthe device of FIG. 1. In this embodiment, the device of FIG. 1 ismodified to replace the integrally formed deflectable retaining memberswith a separately formed ring which is axially retained in the syringebody and which has the deflectable retaining members;

FIG. 33 shows an enlarged partial view of another modified version ofthe device of FIG. 1. In this embodiment, the device of FIG. 1 ismodified to include a locking system to prevent re-use of the device aswell as an optional vent opening. The locking system locks the plungerto the syringe body when the plunger is fully or nearly fully depressed;

FIGS. 34 and 35 each show an enlarged partial view of another embodimentof a plunger which can be used on a device of the type shown in FIG. 1.The plunger is similar to that used in FIG. 1 except that the inner sealis axially retained within the plunger via a recess and frangibleprojection system. In FIG. 35, the inner seal is axially retained withinthe plunger. In FIG. 34, the inner seal has been moved back sufficientlyto cause the inner seal to break the frangible projection of theplunger;

FIG. 36 shows an enlarged partial view of another embodiment of aplunger which can be used on a device of the type shown in FIG. 1. Theplunger is similar to that used in FIG. 1 except that the inner seal isaxially retained within the plunger via a recess and frangibleprojection system. In FIG. 36, the frangible projection of the plungerhas annular v-shaped recesses which weaken the projection so that itbreaks (via shearing forces) in a predictable manner; and

FIG. 37 shows an enlarged partial view of another non-limitingembodiment of a device. The device is similar to that of FIG. 1, exceptthat it utilizes a sealing member that utilizes a sealing member whichcan extend into the opening of the needle which prevents medication frompassing into the needle when it is inserted into the distal end of theneedle. The device also utilizes plural locking members which lock tothe needle unit when the plunger is moved to the fully depressedposition.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings and first to FIGS. 1-17 and 20-26 whichshows a first embodiment of an injection device 1. In embodiments, thedevice is a retractable hypodermic syringe. The syringe includes agenerally elongate cylindrical barrel 10 having a transverse flange 11arranged at a distal end of the barrel 10. The barrel 10 includes a maingenerally cylindrical section 12. A proximal end of the barrel 10includes a reduced diameter section 13. A safety cap 60 is removablydisposed on a proximal end of the syringe body 10.

A needle support 30 has a hub portion 31 that is substantially axiallyretained within a proximal area of the body 10 (see FIG. 3) and includesa rear end surface which can contact an inner seal 25 of a plunger 20 aswill be described in detail below. The needle support 30 also has a mainneedle portion 32 that has a rear end fixed within a needle hub 31 and aproximal end that is pointed or a puncturing end which extends out pastthe proximal end of the syringe body 10. A sealing guide member 50provides sealing between the needle 32 and the syringe body 10, alsoallows the needle 32 to slide into the syringe 1 as will be describedbelow. A spring 40 is arranged within the section 13 and the syringebody 10, and in the configuration shown in FIG. 2, is fully or nearlyfully compresses. The spring 40 biases the needle unit 30 towards adistal end of the syringe 1.

Substantially arranged within the barrel 10 of the syringe is movablydisposed a plunger 20. The plunger 20, like the syringe body 10,includes an end flange 21 which is typically engaged by the thumb of theuser while the transverse flange 11 is engaged by the fingers of theuser in order to enable the plunger 20 to be forced into the barrel 10for the purpose of expelling the medicament from the barrel 10 throughthe needle 32. The plunger 20 additionally includes a generallycylindrical space 22 which is sized to receive therein the needle unit30 (see FIG. 5). A piston 23 (see FIG. 9) is arranged on a proximal endof the plunger 10. The plunger 20 also utilizes a proximal engaging end24 which is sized and configured to engage with deflectable retainingmembers 15 (see FIGS. 6 and 7) when the plunger 20 is fully depressed.An inner seal or sealing member 25 is arranged within the plunger 20. Asis apparent from FIGS. 6 and 7, the seal 25 has frangiblecircumferential projections which are sized and configured to breakand/or shear off when the plunger 20 is depressed to the point where theseal 25 contacts the hub 31. Before the projections of the seal 25break, they provide sealing between the seal 25 and the plunger 20. Thissealing ensures that no medication passes into the plunger space 22until the seal 25 is broken.

As is apparent from FIGS. 6 and 7, to unsure that the needle unit 30 isprevented from moving forwards when the plunger 20 is fully depressed, aplurality of stop projections or ribs 14 are arranged within the section13 of the syringe body 10.

The operation of the device shown FIGS. 1-7 will now be described. Oncethe user obtains the device 1 shown in FIG. 1, he or she can then removethe safety cap 60. The device 1 so shown in FIG. 2 can now be used for,e.g., injection. This can occur when the user injects the needle 32 intoa medication container and withdraws the plunger 20 as shown in FIG. 3.This causes medication fluid to fill the space in the body 10 betweenthe plunger piston 23 and seal 25 and the sealing member 50. As thispoint, the user can move the plunger 20 forwards slightly to remove anyair in the syringe 1. The needle 32 can then be injected into, e.g.,tissue. Then, the user will depress the plunger 20 to cause themedication to pass out of the needle 32. Once fully or nearly fullydepressed, the proximal end 24 of the plunger 20 contacts thedeflectable retaining members 15 (see FIGS. 6 and 7) and causes them todeflect out of locking and/or retaining engagement with the hub 31.Since engagement between the deflectable retaining members 15 and thehub 31 is the only mechanism which presents the spring 40 from movingthe needle unit 30 backwards, once this engagement is removed, theneedle unit 30 will be forced backwards by the spring 40. Also, oncefully or nearly fully depressed, the seal 25 of the plunger 20 contactsthe rear surface of the hub 31 (see FIGS. 6 and 7). Since the ribs 14prevent any forward movement of the hub 31, contact between the seal 25and the hub 31 causes the frangible sealing projections of the seal 25to shear or break. At this point, the spring 40 automatically expandsaxially and pushes the needle unit 30 and seal 25 into the space 28disposed inside the plunger 20 as shown in FIG. 5. This action withdrawsthe needle 32 into the syringe and renders the device 1 unusable. Thedevice 1 of FIG. 5 can then be safely disposed of without the userhaving to worry about being accidently pricked by the needle 32, whichis safely disposed inside the plunger 20.

In embodiments, the engagement between the deflectable retaining members15 and the hub 31 is removed or disengages prior to the sealingengagement between the seal 25 and the plunger 20. In other embodiments,the engagement between the deflectable retaining members 15 and the hub31 is removed or disengages just prior to the sealing engagement betweenthe seal 25 and the plunger 20. In embodiments, the engagement betweenthe deflectable retaining members 15 and the hub 31 is not removed ordisengaged until after the frangible sealing engagement between the seal25 and the plunger 20 is broken. In embodiments, the engagement betweenthe deflectable retaining members 15 and the hub 31 is not removed ordisengaged until just after the frangible sealing engagement between theseal 25 and the plunger 20 is broken. In embodiments, the force requiredto unlock or remove the engagement between the deflectable retainingmembers 15 and the hub 31 is less than that required to break thesealing engagement between the seal 25 and the plunger 20. Inembodiments, the force required to unlock or remove the engagementbetween the deflectable retaining members 15 and the hub 31 is greaterthan that required to break the sealing engagement between the seal 25and the plunger 20. In embodiments, the force required to unlock orremove the engagement between the deflectable retaining members 15 andthe hub 31 is substantially equal to that required to break the sealingengagement between the seal 25 and the plunger 20. In embodiments, anoise is produced (providing an auditory signal to the user) when theengagement between the deflectable retaining members 15 and the hub 31is removed. In embodiments, a noise is produced (providing an auditorysignal to the user) when the sealing engagement between the seal 25 andthe plunger 20 is broken. In embodiments, a visual indication isproduced (providing a visual signal to the user) when the engagementbetween the deflectable retaining members 15 and the hub 31 is removed.In embodiments, a visual indication is produced (providing a visualsignal to the user) when the sealing engagement between the seal 25 andthe plunger 20 is broken. Such visual indicators can be facilitated bymaking the plunger 20 and body 10 substantially transparent and/ortranslucent.

FIGS. 8 and 9 show views of the plunger 20 used on the firstnon-limiting embodiment shown in FIG. 1. The plunger 20, in embodiments,is a one-piece integrally formed member to which is axially secured apiston 23 and an inner seal 25. The plunger 20 includes a distal flange21, a main cylindrical section 22, a generally cylindrical proximal end24, one or more inner generally circumferential tapered recesses 26, agenerally cylindrical recess 27 sized and configured to receive thereinand axially retain the piston 23, and a generally cylindrical space 28.

FIGS. 8 and 9 show views of the piston 23 used on the plunger of FIGS. 8and 9. The piston 23, in embodiments, is a one-piece integrally formedmember to which is axially secured within the recess 27 of the plunger20. In embodiments, it can be substantially similar at pistonsconventionally used in syringes which include plural externalcircumferential sealing projections.

FIGS. 12-14 show views of the inner seal 25 used on the plunger of FIGS.8 and 9. The seal 25, in embodiments, is a one-piece integrally formedmember to which is axially secured to an inner portion of the plunger20. In embodiments, the seal 25 includes a distal or rear surface 25 a,one or more tapered external circumferential projections 25 b, and aproximal surface 25 c. The one or more tapered external circumferentialprojections 25 b each extend into one of the recesses 26 of the plunger20. The tapered external circumferential projections 25 b are designedto be frangible and sized and configured to shear upon experiencing apredetermined force applied to the surface 25 c. The shape, i.e.,rearward orientation, of the tapered external circumferentialprojections 25 b is such that a force applied to the surface 25 c willcause the projections 25 b to grip recesses 26 by a greater amount andsuch that a force applied to the surface 25 a will cause the projections25 b to grip recesses 26 by a lesser amount. In embodiments, a forceapplied to the surface 25 a will cause the projections 25 b to start tomove out of engagement with the recesses 26 by a significant amountwithout breaking.

FIGS. 15-17 show how the syringe body 10 used on the device of FIG. 1receives therein the seal guide 50, the needle member 30 and the spring40 before receiving therein the plunger 20 of FIGS. 8 and 9. The body10, in embodiments, is a one-piece integrally formed member. The body 10includes a distal flange 11, a main cylindrical section 12, a generallycylindrical proximal end 13, one or more inner radially orientedspaced-apart ribs 14, plural delectable retaining members 15 which areequally spaced-apart and which are sized and configured to engage withthe circumferential recess 33 of the needle unit 30 (see FIG. 20), and agenerally cylindrical opening 17 sized and configured to receive therein(in a sealing and/or press-fit manner) the generally cylindrical surface50 a of the sealing guide 50 (see FIG. 26). In embodiments, twooppositely arranged delectable retaining members 15 are utilized. Inembodiments, three equally spaced delectable retaining members 15 areutilized. In embodiments, between four and eight equally spaceddelectable retaining members 15 are utilized. FIG. 18 shows an optionalembodiment wherein section 13′ utilizes four equally spaced delectableretaining members 15′ and four ribs 14′ which have the same orientation.FIG. 19 shows an optional embodiment wherein section 13″ utilizes fourequally spaced delectable retaining members 15″ and four ribs 14″ whichare offset with respect to one another. These systems/configurations canbe utilized on any of the herein disclosed device embodiments.

FIGS. 20-22 show views of the needle unit 30 used on the device 1 ofFIG. 1. The needle unit 30, in embodiments, can be a one-pieceintegrally formed member. The needle unit 30, in embodiments, utilizes aone-piece needle hub 31 and a one-piece needle 32 that has a distal endsecured (e.g., press-fit) within an opening the hub 31. The needle hub31, in embodiments, also utilizes a tapered section 36 and acircumferential groove or recess 33 which can receive therein the freeends of the deflectable gripping members 15 (see FIG. 6). Inembodiments, the needle 32 has a main lumen 34 and a puncturing end 35.In embodiments, the needle 32 can be substantially similar at pistonsconventionally used in syringes which include plural externalcircumferential sealing projections.

FIGS. 23 and 24 show views of the spring 40 used on the embodiment ofFIG. 1. FIG. 23 shows the spring 40 in an expanded or relaxed position.In the position shown in FIG. 1, the spring 40 is fully or nearly fullycompressed. Expansion of the spring 40 causes the needle unit 30 toretract fully into the plunger 20 (see FIG. 5).

FIGS. 25 and 26 show views of the sealing guide 50 used on theembodiment of FIG. 1. The seal 50 has a generally cylindrical section 50a, a tapered section 50 b, and a generally cylindrical opening 50 c. Thegenerally cylindrical section 50 a is sized and configured to sealinglyand frictionally engage with opening 17 in the body 10. The taperedsection 50 b is sized and configured to sealingly and frictionallyengage with a corresponding tapered surface of the body 10. Thegenerally cylindrical opening 50 c is sized and configured to sealinglyengage with the needle 32. The seal 50, in embodiments, can be aone-piece integrally formed member.

FIG. 27 shows an enlarged partial view of another embodiment of aplunger 20′ which can be used on a device of the type shown in FIG. 1.The plunger 20′ is similar to that used in FIG. 1 except that the innerseal 25′ is axially retained within the plunger 20′ via a separatelyformed ring 29′. The ring 29′ is seated in a circumferential recessformed in the seal 25′. In embodiments, a distal circumferentialshoulder is sized and configured to break when the plunger 20′ is fullydepressed. In embodiments, a ring 29′ is a frangible ring and is sizedand configured to break when the plunger 20′ is fully depressed. As withthe previous embodiments, the plunger 20′ includes a proximal engagingend 24′ and a piston 23′. This system/configuration can be utilized onany of the herein disclosed device embodiments.

FIG. 28 shows an enlarged partial view of a modified version of thedevice of FIG. 1. In this embodiment, the device of FIG. 1 is modifiedto include a puncturable sealing washer 70 to provided sealing betweenthe needle 32′ and the guide 50 and/or syringe body 10′″. The needleunit 30′ is also modified to include a generally cylindrical section37′. As with the previous embodiments, the device utilizes ribs 14′″ anddeflectable retaining members 15′″. This system/configuration can beutilized on any of the herein disclosed device embodiments.

FIGS. 29-31 show views of another modified version of the device ofFIG. 1. In this embodiment, the device of FIG. 28 is modified to removethe ribs and the guide seal and instead sealing is provided between theopening 17 ^(IV) of the syringe body 10 ^(IV) and the needle 32′. Aswith the previous embodiments, the device utilizes deflectable retainingmembers 15 ^(IV). This system/configuration can be utilized on any ofthe herein disclosed device embodiments.

FIG. 32 shows an enlarged partial view of another modified version ofthe device of FIG. 1. In this embodiment, the device of FIG. 1 ismodified to replace the integrally formed deflectable retaining memberswith a separately formed ring 16 ^(V) which is axially retained in thesyringe body 10 ^(v) via a projection and recess securing arrangement.The ring 16 ^(v) is a one-piece member that has the deflectableretaining members 15 ^(v). This system/configuration can be utilized onany of the herein disclosed device embodiments.

FIG. 33 shows an enlarged partial view of another modified version ofthe device of FIG. 1. In this embodiment, the device of FIG. 1 ismodified to include a locking system to prevent re-use of the device aswell as an optional vent opening. The locking system has the form of oneor more projections LP and one or more recesses LR adapted to receivetherein the locking projection LP. The locking system locks the plunger120 to the syringe body 110 when the plunger 120 is fully or nearlyfully depressed. Other configurations can also be utilized such asarranging the locking projections LP on the syringe body 110 and thelocking recesses LR on the plunger 120. The projection LP can be, inembodiments, continuous or intermittent and the recess LR can be acircumferential recess. The device can also be modified to utilize anoptional vent opening VO in the plunger 120. The locking system preventsre-use of the device. The systems shown in FIG. 33 can be utilized onany of the herein disclosed device embodiments.

FIGS. 34 and 35 each show an enlarged partial view of another embodimentof a plunger which can be used on a device of the type shown in FIG. 1.The plunger is similar to that used in FIG. 1 except that the inner seal125′ is axially retained within the plunger body 122′ via a recess andfrangible projection FP. In FIG. 35, the inner seal 125′ is axiallyretained within the plunger. In FIG. 34, the inner seal 125′ has beenmoved back sufficiently under the action of a force F to cause the innerseal 125′ to break the frangible projection FP of the plunger. Thesystems shown in FIGS. 34 and 35 can be utilized on any of the hereindisclosed device embodiments.

FIG. 36 shows an enlarged partial view of another embodiment of aplunger which can be used on a device of the type shown in FIG. 1. Theplunger is similar to that used in FIG. 1 except that the inner seal125″ is axially retained within the plunger body 122″ via a recess and aselectively weakened frangible projection FP'. In FIG. 36, the frangibleprojection FP' of the plunger has annular v-shaped recesses which weakenthe projection FP' so that it breaks (via shearing forces) in apredictable manner. The system shown in FIG. 36 can be utilized on anyof the herein disclosed device embodiments.

FIG. 37 shows an enlarged partial view of another non-limitingembodiment of a device. The device is similar to that of FIG. 1, exceptthat it utilizes a sealing member 25″ that utilizes a sealing member SMwhich can extend into the distal opening of the needle 32″ so as toprevent medication from passing into the needle 32″ when it is insertedinto the distal end of the needle 32″. The device also utilizes plurallocking members LM which lock to a circumferential engaging projectionEP of the needle unit 31″ when the plunger is moved to the fullydepressed position (indicated by arrow). Once locked to each other, theseal 25″ and needle unit 30″ retract into the plunger as a unit. Thesystem shown in FIG. 37 can be utilized on any of the herein discloseddevice embodiments.

The devices described herein can also utilize one or more featuresdisclosed in prior art documents expressly incorporated by reference inpending U.S. patent application Ser. No. 11/616,196 (Publication No.2008/0154212). This application and the documents expressly incorporatedtherein is hereby expressly incorporated by reference in the instantapplication. Furthermore, one or more of the various parts of the devicecan preferably be made as one-piece structures by e.g., injectionmolding, when doing so reduces costs of manufacture. Non-limitingmaterials for most of the parts include synthetic resins such as thoseapproved for syringes, blood collection devices, or other medicaldevices. Furthermore, the invention also contemplates that any or alldisclosed features of one embodiment may be used on other disclosedembodiments, to the extent such modifications function for theirintended purpose.

It is noted that the foregoing examples have been provided merely forthe purpose of explanation and are in no way to be construed as limitingof the present invention. While the present invention has been describedwith reference to an exemplary embodiment, it is understood that thewords which have been used herein are words of description andillustration, rather than words of limitation. Changes may be made,within the purview of the appended claims, as presently stated and asamended, without departing from the scope and spirit of the presentinvention in its aspects. Although the present invention has beendescribed herein with reference to particular means, materials andembodiments, the present invention is not intended to be limited to theparticulars disclosed herein; rather, the present invention extends toall functionally equivalent structures, methods and uses, such as arewithin the scope of the appended claims.

1. An injection device comprising: a barrel; a hollow plunger having aportion structured and arranged to move within the barrel; a needleunit; and a safety system that one of automatically causes the needleunit to retract into the plunger when the plunger reaches asubstantially fully depressed position; and utilizes a frangible orbreakable seal arranged within the plunger.
 2. The injection device ofclaim 1, wherein the injection device is a single-use syringe.
 3. Theinjection device of claim 1, wherein the barrel comprises acylindrically shaped internal space structured and arranged to receivetherein a medicine.
 4. The injection device of claim 3, wherein thebarrel further comprises a proximal opening within which the needle unitis at least one of: press fit; and in sealing engagement therewith. 5.The injection device of claim 1, wherein the plunger comprises a pistonarranged at a proximal area of the plunger and an actuating end arrangedin front of the piston.
 6. The injection device of claim 5, wherein theplunger further comprises at least one of: the piston being an elastomeror rubber piston; a hollow space sized and configured to receive thereinthe needle unit in its entirety; and a locking member adapted to lockwith a locking member arranged on the barrel.
 7. The injection device ofclaim 1, wherein the barrel, the plunger, and a hub portion of theneedle unit each comprise a synthetic resin material.
 8. The injectiondevice of claim 1, wherein the needle unit comprises a generallycylindrical hub and a hollow needle projecting from the hub.
 9. Theinjection device of claim 8, wherein the needle comprises at least oneof metal and stainless steel.
 10. The injection device of claim 1,wherein the barrel comprises at least one releasable retaining memberwhich releasably retains the needle unit in an initial position.
 11. Theinjection device of claim 1, wherein the barrel comprises pluralreleasable retaining members which each releasably retain the needleunit in an initial position.
 12. The injection device of claim 1,wherein the barrel comprises at least one deflectable retaining memberwhich releasably retains the needle unit in an initial position.
 13. Theinjection device of claim 1, wherein the barrel comprises pluraldeflectable retaining members which each releasably retain the needleunit in an initial position.
 14. The injection device of claim 1,further comprising at least one of: a locking arrangement that isstructured and arranged to lock the needle unit to the frangible orbreakable seal; and a plugging system that is structured and arranged toplug a distal end of a lumen of the needle unit.
 15. The injectiondevice of claim 1, further comprising a locking arrangement selectivelylocking a portion of the plunger to the barrel upon the plunger reachinga substantially fully depressed position.
 16. The injection device ofclaim 1, further comprising a biasing member, wherein, when the plungeris moved to a full injection position, the needle unit is automaticallycaused to retract into the plunger via the spring.
 17. The injectiondevice of claim 1, further comprising a spring arranged within thebarrel, wherein, when the plunger is moved to a full injection position,the needle unit is automatically caused to retract into the plunger viathe spring.
 18. The injection device of claim 1, further comprising asystem providing an indication to the user that further forward movementof the plunger will cause the needle unit to automatically retract intothe plunger.
 19. The injection device of claim 1, further comprising asystem providing an indication to the user that at least one of: theplunger has reached a full injection position; and the further forwardmovement of the plunger will cause the needle unit to automaticallyretract into the plunger.
 20. A syringe comprising: a barrel; a plungerhaving a portion structured and arranged to move within the barrel; aneedle unit; and a safety system that one of: automatically causes theneedle unit to retract into the plunger when the plunger reaches asubstantially fully depressed position; and utilizes a frangible orbreakable seal arranged within the plunger.
 21. The syringe of claim 20,further comprising a system providing an indication to the user that theplunger has reached a full injection position and the further forwardmovement of the plunger will cause the needle unit to automaticallyretract into the plunger.
 22. A single-use syringe comprising: a barrel;a hollow plunger having a portion structured and arranged to move withinthe barrel; a needle unit; and a safety system that one of automaticallycauses the needle unit to retract into the plunger when the plungerreaches a substantially fully depressed position; and utilizes afrangible or breakable seal arranged within the plunger.
 23. The syringeof claim 22, further comprising a system providing an indication to theuser that the plunger has reached a full injection position and thefurther forward movement of the plunger will cause the needle unit toautomatically retract into the plunger.
 24. A method of using theinjection device of claim 1, the method comprising: moving the plungeraway from the needle unit so as to cause a desired amount of medicine toenter into the barrel; moving the plunger towards the needle unit so asto cause medicine to exit the barrel through the needle.
 25. The methodof claim 24, further comprising locking the plunger to the barrel toprevent re-use of the syringe.
 26. An injecting device comprising atleast one feature shown in at least one the drawings of the instantapplication.